This proposal consists of four subprojects. The first subproject deals with production of a panel of monoclonal antibodies (mAbs) directed against the major outer membrane porin proteins OmpC, OmpF, and OmpD of Salmonella typhimurium, and characterization and use of these antibodies in antigenic analysis of porins and localization of mAb-specific epitopes on intact bacterial cell surface. The long-term objective of this project is to gain information which would help elucidate the molecular structure and functioning of the outer membrane proteins of gram-negative bacteria, and the regulatory processes that presumably are common to both prokaryotic and eukaryotic cells. In the second subproject, acid rain in central Alabama will be studied by the Proton Induced X-ray Emission techniques by irradiating samples with a proton beam from a 3MV Dynamitron accelerator, and analyzing the X-ray spectra for trace element concentrations. The long-term objective of this project is to establish a reliable data base which will be useful in evaluating the effects of acid rain, and in long-range planning for development and evaluation of abatement strategies. In the third subproject, sulfhydryl enzymes will be treated with selected oxidants, and the effect of these treatments on sulfhydryl content and enzymatic activity will be determined. These studies seek to discover reactions which would serve as models for thiol-disulfide interchange reactions which may be involved in regulation of sulfhydryl enzyme activities in vivo. The fourth subproject deal with analysis of the mitogenic action of iron (Fe3+) and biotin of avian sarcoma virus-transformed cells. The long-range goal of this study is to assess the possible synergistic action of iron and biotin in stimulating the growth of tumor cell in vivo. Minority studies will participate in every phase of these research projects.